The present invention relates to telecommunications systems. More particularly, the present invention relates to an apparatus that allows direct telecommunications between two computer systems only under restricted and predefined circumstances.
Telephone companies have begun to offer to their customers a system called "CALLER ID." This system enables a customer, after having purchased special receiving equipment from their telephone company, to view the telephone number of the person calling them. The CALLER ID system sends a signal to the special receiving equipment and displays the telephone number of the caller on a liquid crystal display (LCD). With the telephone number of the caller known, the customer can make an informed decision about whether or not to answer the telephone.
In recent years, unauthorized access to computer systems has become a serious problem. Unauthorized users, called hackers, place a telephone call to the computer system to which they wish to access. Upon establishing the telephone link, the hacker is prompted by the computer network to supply his user-name and password. Instead of providing a legitimate user-name and password, the hacker uses his custom software to circumvent the password protection system and gain access to the network operating system. Once "in" the network, the hacker can read and modify files containing sensitive information. The hacker also has the ability to destroy large numbers of computer files and reek havoc within the network--causing many thousands of dollars in damages. As a lasting legacy, a hacker may leave a computer software virus that can cause even more damage to the computer network. More than 5000 viruses currently exist and hundreds are created each month. These viruses cause millions of dollars in damages each year. The complexity and sophistication of the virus software programs is continually met by equally determined efforts, on the part of network administrators, to prevent their use. This has led to a "cat-and-mouse" game between the network administrators and the hackers. As anti-viral network protection becomes more sophisticated, the hackers get smarter and more determined.
The threat of viruses and hackers is so potent that a whole industry has evolved to counter that threat. Anti-virus software is now widely available. Large networks, which utilize telecommunications to allow remote users to link into the network, have adopted software "firewalls." Firewalls are software programs that are designed to prevent unauthorized access to network operating systems and sensitive data. Unfortunately, effective firewalls are so expensive that smaller capitalized networks are forced to do without effective protection. Furthermore, the determination and technical abilities of hackers ensures that some will get through the firewalls or other defenses and damage the network.
Home businesses and telecommuters, who rely on facsimile/modem features of their personal computers (PC) in the course of their business, are susceptible to unwanted facsimile messages and unauthorized access to their PC's operating system and data files. Home users generally lack the sophistication and resources of the network administrator. Proper back-up procedures, which are common in major network systems, are less likely to be implemented in the home-based system. These facts make home-based systems even more vulnerable to the hacker's evil efforts.
There is, therefore, a need in the art for inexpensive and effective prevention of unauthorized access to computer networks and PCs. It is an object of the present invention to remedy problems in the prior art.